Method of making a moulded body of foam plastics material

Abstract

The present invention relates to a method for the manufacture of moulded bodies such as cornices from foam plastics material, the visible side of these bodies being heavily textured or profiled, smooth, non-porous and free from separation elements, with a unit weight of less than 200 kg/m 3 . In the method, a thin, elastic, heat-deformable film (3) is inserted between two heated mould portions (1, 2) in such a way that the film edges are clamped between the superimposed mould edges of the two mould portions (1, 2), a reactive, heat emitting, foaming plastics mixture is introduced through the upper mould portion (1) in such a way that it may be distributed on the film, and the hollow chamber formed between the film and the lower mould portion is evacuated during foaming, such that the film intimately conforms to the shape of the lower mould portion.

We claim: 
     
       1. A method fo making molded article of foam plastic material with a complicated sharp textured surface profile structure, which is smooth, non-porous and free from mold release agent, comprising the following steps: (a) a thin, elastic, heat-deformable film is inserted between two heated mold portions so that the film edges are clamped between the superimposed mold edges of the two mold portions and the film lies flat between both mold portions,   (b) a reactive, heat emitting, foaming plastic mixture is introduced through the upper mold portion and distributed on the film, and   (c) the hollow chamber formed between the film and the lower mold portion is evacuated during foaming, so that the film which is heated both by the heated mold portions by heat radiation and by the heat of reaction given off by the reaction mixture is pressed by the foam pressure together with the vacuum provided so that its contours accurately fit the complicated textured or profiled mold surface of the lower mold portion.   
     
     
       2. A method according to claim 1 wherein the moulded body has, by contact with the second mold member a heavily textured or profiled, smooth nonporous surface. 
     
     
       3. A method according to claim 1 wherein the moulded body is of a density of less than 200 kg/m -3 . 
     
     
       4. A method according to claim 1 wherein the film is of a thickness of 180-250 um. 
     
     
       5. A method according to claim 1 wherein the film is of soft polyvinyl chloride. 
     
     
       6. A method according to claim 1 wherein the two mould portions are heated to 55° to 65° C. 
     
     
       7. A method according to claim 1 wherein said foaming plastics material comprises a two component mixture producing a hard polyurethene foam. 
     
     
       8. A moulded body produced by the method of claim 1.